Liquid ejection head, manufacturing method thereof, and image forming apparatus

A liquid discharge head, comprising:

• a plurality of ejection ports which eject liquid;
• a plurality of pressure chambers which communicate respectively with the plurality of ejection ports;
• a plurality of piezoelectric elements which deform the plurality of pressure chambers respectively and are provided on a side of the pressure chambers opposite to a side on which the ejection ports are formed;
• a common liquid chamber which supplies the liquid to the plurality of pressure chambers and is formed on a side of the piezoelectric element opposite to the pressure chambers;
• and
• a plurality of electric wires which stand upright from and substantially perpendicular to a surface on which the piezoelectric elements are mounted, the electric wires passing through a partition wall of the common liquid chamber and being electrically connected to the piezoelectric elements, the electric wires being formed of metal strings.

A manufacturing method for a liquid ejection head comprising:

• a plurality of ejection ports which eject liquid;
• a plurality of pressure chambers which communicate respectively with the plurality of ejection ports;
• a plurality of piezoelectric elements which deform the plurality of pressure chambers respectively and are provided on a side of the pressure chambers opposite to a side on which the ejection ports are formed;
• a common liquid chamber which supplies the liquid to the plurality of pressure chambers and is formed on a side of the piezoelectric element opposite to the pressure chambers, the method comprising the steps of:
• forming holes in a member which forms a partition wall of the common liquid chamber, the holes passing through the partition wall substantially perpendicularly to a surface on which the piezoelectric elements are mounted;
• then forming electric wires by stacking wiring material for forming the electric wires connected electrically to the piezoelectric elements onto the member for forming the partition wall of the common liquid chamber, and by applying pressure to the stacked wiring material to insert the wiring material into the holes formed in the partition wall of the common liquid chamber, and
• then joining a separately-formed lower layer part of the liquid ejection head which includes the pressure chambers having the piezoelectric elements and the ejection ports, to the member forming the partition wall of the common liquid chamber, into which the wiring material has been inserted.

A manufacturing method for a liquid ejection head, comprising the steps of:

• stacking, at a predetermined interval, a plurality of base plates each formed with holes in predetermined positions, and passing metal strings through the holes;
• then forming a sacrificial layer between the base plates;
• then cutting each of the metal strings in a predetermined position of the sacrificial layer on a plane substantially parallel to the base plates;
• then removing the sacrificial layer through melting to form an upper layer portion of the liquid ejection head comprising the metal strings which serve as electric wires extending substantially perpendicular to the base plates;
• then applying a conductive agent to electrode connection portions of a separately-formed lower layer portion of the liquid ejection head which includes pressure chambers having piezoelectric elements and ejection ports, the electrode connection portions being for connection with tip end portions of the metal strings;
• and
• then joining the upper layer portion and the lower layer portion to form the metal strings into electric wires which stand upright from the electrode connection portions substantially perpendicularly to the piezoelectric elements and pass through a common liquid chamber formed on the pressure chambers.